a1=580a2=500a3=(a1+a2)/2a4=(a1+3a2)/4a5=(3a1+5a2)/8a6=(5a1+11a2)/16。。丛空和。。。。。。渗盯。亏孙。an=[(2n-7)a1+[2^(n-2)-(2n-7)]a2]/2^(n-2)a100=[(193*580+(2^98-193)*500]/2^98=500
526
3
540,520,530,525,527.5,526.25,526.875,……526